<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    .box {
        width: 1200px;
        height: 200px;
        background-color: red;
        margin: 100px auto;
    }
    .header {
        width: 100px;
        height: 100px;
        background-color: pink;
    }
    .main {
        border-radius: 50%;
        width: 20px;
        height: 20px;
        background-color: blue;
    }
    .footer {
        width: 50px;
        height: 50px;
        background-color: skyblue;
    }
    </style>
</head>
<body>
    <div class="box">
        <div class="header">

        </div>
        <div class="main"></div>
        <div class="footer"></div>
    </div>
</body>
</html>